<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
	</body>
	<script type="text/javascript">
		var str = "abc";
		
		var strObj = new String("abc");
		strObj.aaa = 111;
		console.log(strObj);
		console.log(typeof strObj);
		console.log(strObj.aaa);
		
		str.aaa = 111;
		console.log(str.aaa);
		console.log(str.length);
		console.log(str.indexOf("c"));
	</script>
</html>
